Analyzing Usage of Indoor Space from Ecological Aspects Based on Constraint-Oriented Fuzzy Sets

A first work piece for forming a tube body (3) made of a carton blank which is coated with a fuseable plastic material on one side and which is provided with an opening in the center thereof. In this opening, a second work piece is inserted and fused having a socket and a collar for forming a discharge opening (7). Thereafter, the blank is folded in such a manner that two walls (3a) are generated which are connected with a center segment (3d) having a lens shaped contour containing the discharge opening (7). Thereafter, the side edges of the walls (3a) are fused with each other in pairs, but the end of the tube body (3) facing away from the discharge opening (7) remains open. Subsequently, filler material is filled through the opening and thereafter the edges (3c) of the wall facing the discharge opening (7) are also fused. In this manner, tube like containers can be made, which can be also closed at the discharge end by the first work piece which consists of comparable inexpensive material.